Extended version of Doctrine_Hydrator_ScalarDriver, passes its _gatherRowData
function a value of false for $aliasPrefix in order to cause it to generate the
sorts of array keys one would see in a HYDRATE_ARRAY type return. Note: This
hydrator will have issues with fields in the return that have the same name
(such as 2 fields each called id) -- the second field value will overwrite the
first field.